In Situ Alkylated Graphene as Oil Dispersible Additive for Friction and Wear Reduction

Alkylated graphene (AGN) with an excellent oil dispersion property was synthesized using an in situ alkylation reaction. The structure and morphology of AGN were characterized by Fourier transform-infrared spectroscopy, X-ray powder diffraction, Thermogravimetric analysis, and transmission electron microscopy and the results indicate that long alkyl chains was successfully grafted on the surfaces of graphene sheets. Tribology properties of AGN as friction-reduction and wear-resistance additive in hydroisomerization dewax base oil (VHVI8) were evaluated using a four-ball machine. The results show that the friction coefficient (COF) and wear scar diameter (WSD) were reduced by 10.9% and 23.0% compared with bare VHVI8 base oil. The friction-reduction and wear–resistance properties are attributed to the stable dispersion, nanobearing mechanism, and ultimate strength of AGN.